[feat]: 下载时根据域名匹配使用指定的HTTP单服务器最大连接数

Problem

　　平时Motrix Next设置了HTTP单服务器最大连接数为16，下载AMD驱动时会秒级触发封控，喜提BAN。 　　AMD驱动下载：https://www.amd.com/zh-cn/support/downloads/drivers.html/graphics/radeon-rx/radeon-rx-9000-series/amd-radeon-rx-9070-xt.html 　　经过多轮测试，当HTTP单服务器最大连接数为2时，连续多次下载驱动不会导致被封控。大于这个连接数就很容易被禁，甚至都没等下载完就被禁了。 　　

Proposed solution

　　希望能支持域名匹配使用指定的下载连接数，记得其他下载器的话，IDM是有这个设置项。

Alternatives considered

No response

Additional context

No response

Validations

• I have searched the existing issues and this feature has not been requested before.
• I have read the Contributing Guide and understand that new features require an approved issue before a PR is submitted.
• This request belongs to the Motrix Next desktop app, not the browser extension, download engine, or a usage question.